Nobody in London wanted to stand in the way of the exciting (and profitable) new markets in forward rate agreements and loan syndication. Self-regulation was the way forward. What could possibly go wrong?

We know now that what developed was a "cesspit", as Paul Tucker, a deputy governor of the Bank of England, put it. The BBA plainly failed to spot the abuses or imagine that Bollinger boys at Barclays and elsewhere could try to manipulate and co-ordinate submissions. Self-regulation failed and the reputation of London was damaged.

The BBA will now be cleared off the Libor pitch and external regulation imposed. That is clearly necessary. But a mass of technical issues remain for Martin Wheatley, the Financial Services Authority official leading the inquiry, to address in his report on Friday. For example: how do you switch to surer benchmarks based on actual lending if there are no transactions on a given day in some of the markets? Remember, there is no single Libor rate; instead there are benchmarks covering 15 borrowing periods in 10 different currencies.

That's one detailed puzzle for Wheatley to solve. But his main proposal should be easy: make it a criminal act to try to manipulate Libor.